ON THE ACTION OF DIURETICS. 
645 
it passes ; able to calm too high irritation and diminish or even 
completely arrest the nervous super-secretion of which they might 
be the seat, &c. 
The diminution of the natural acridity of the urinary discharges, 
and their violet odour, under the influence of balsamic diuretics, are 
two important facts in the history of these medicines which it be- 
comes of importance for us to examine. 
Such medicines being by nature acrid, it is curious enough that 
they should possess the property of diminishing acridity in the 
urine. This cannot be explained entirely by the state of extreme 
division in which they may be when they reach the kidneys ; for 
this is a state which produces simple attenuation of property and 
not the radical change that is observed. So that it follows, that 
their components must have undergone some change in their nature 
in the blood, whether it be the consequence of respiration, or, 
which to us is more probable, through the action of the alkaline 
ingredients of this fluid, which would tend to form soapy com- 
pounds with the resins, the gum-resins, and the essences. Indeed, 
this seems to be indicated at the time by the nature of the urine 
and the development of the violet odour, as we have already 
pointed out. 
Concentrated essences always have a less fragrant odour than 
such as are in a state of extreme division, as they exist by nature 
in parts of such vegetables as produce them, and often, indeed, the 
odour is altogether of another kind. According to this, we may 
attribute the change of odour experienced, in the animal economy, 
by the essential oil of turpentine, for example, to its state of attenu- 
ation in the organic cullenders. This, however, goes for nothing, 
since it is ejected through the skin and bronchial tubes without any 
change of odour, while that excreted through the urinary passages 
always possesses a strong violet odour. 
To what, then, are we to attribute this change of odour 1 Evi- 
dently to a chemical modification of the essence, since our chemist 
(M. Deville) has recently succeeded in transforming it into essence 
of lemon. But whence comes such a change 1 It is not in the 
digestive canal, since the oil of turpentine, reduced to vapour and 
inhaled, rapidly communicates a violet odour to the urine. Is it 
in the blood ! Nothing goes to prove this, because the expired air 
and the perspiration never have any other odour but that of the 
spirits of turpentine. It is, consequently, to all appearance, in the 
urinary passages even that this transformation takes place. How 
is it accomplished I It would be difficult to say before experi- 
mental inquiry has taught it us. Nevertheless, we believe it is 
the azotic principles, and especially the saline ingredients, of the 
urine which work this modification. Without, however, any de- 
VOL. XXIII. 4 R 
